It was hardly a vintage display from Alan Buckley's Mariners but it sent an above average crowd home happy with an early Christmas present of three points.
Torquay scarcely looked a second from bottom side but they had a chronic lack of a cutting edge despite playing some neat football.
Grimsby took an early lead when, after a defensive lapse, the persistence of Martin Paterson set up fellow striker Isaiah Rankin who scrambled home his second goal of the season.
That came in the 18th minute but Grimsby were unable to capitalise until 12 minutes from time when they added a second goal.
In the first half Town gave the ball away far too much to allow Torquay to have as much, if not more, of the game.
But the second-half substitution of central midfielder Ciaran Toner for wideman Nick Heggarty enabled Grimsby to impose themselves more on the visitors.
But, after striker Chris McPhee missed a great chance on 74 minutes, Grimsby wrapped things up with a second goal four minutes later.
Defender Tom Newey swung over a corner and central defender and skipper Nick Fenton rose unchallenged to head powerfully home.
There was still time for Paterson to force a good block out of keeper Nathan Abbey as the game ran away from the hapless visitors.
The result leaves Torquay's plight at the foot of the table a serious one and, despite having an FA Cup third round home tie against Championship side Southampton to look forward to, they are once again fighting for their Football League future.
Grimsby, on the other hand, who, not many weeks ago, were in serious trouble themselves, can now see mid-table in their sights as they continue their improvement under Buckley, who is back in charge of the club for a third time.